天津滨海新区软土地基路堤沉降规律研究

《天津滨海新区软土地基路堤沉降规律研究》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、摘要基于软土区域路基压缩性高、沉降大、固结变形持续时间长等特点，本文结合天津滨海新区南港工程部分断面沉降观测数据，对软土地基的沉降机理及其发展规律以及沉降量的预测方法等进行了探讨，取得了如下主要成果：1.阐述了天然软土的变形破坏机理，提出了从弹塑性力学角度出发，天然软土沉降变形的三个阶段；采用荷载与沉降速率曲线拐点分析法分析了该软土区域的沉降变形规律；在填土高度超过2m以后，绝大部分施工期沉降已经完成。后续沉降很小，沉降速率迅速减小。2.利用双曲线法对超载实测沉降曲线的拟合，验证了预压处治方法的有效应力系数；采用双曲线预测了软土地基的最终沉降，并得到了较好的拟合效

2、果。3.分析得出在软土地区路基工程中，沉降系数随填土高度、密度、速率的增加而增大，随着硬壳层的厚度，软土厚度和强度的增加而减小，随着地基处理类型从单纯预压类→竖向排水体类→复合地基类→挤密桩类的变化而减小。4.结合工程实际，按沉降系数公式计算得到的沉降系数要大于反算所得的沉降系数，由于偏大的数值对工程来说是偏于安全的，所以在设计中采用沉降系数公式计算所得的沉降系数是可行的。关键词：道路工程软土路基变形规律双曲线沉降预测控制措施IIIAbstractBasedonthecharactersofsubgradesuchashighcompression,largese

3、ttlementandlongtimeconsolidationdeformationinsoftsoilregion,combinedwithsettlementobservationdataofsomesectioninacertainengineeringofBinhaiNewAreainTianjin,thispaperdiscussedonthesettlementmechanism,developmentlawandsettlementforecastmethodofsoftsoilfoundation,mainresultsweremadeasfol

4、lowing:1.Deformationdamagemechanismofnaturalsoftsoilwasdescribed,thethreestagesofsettlementdeformationofnaturalsoftsoilwereputforwardfromtheangleofelastic-plasticmechanics;settlementdeformationlawofthesoftsoilregionwasanalyzedbyusingloading-settlementratecurveinflectionpointmethod;aft

5、erfillingheightexceeding2m,mostsettlementhadbeencompletedduringconstruction.Subsequentsettlementwassmallandsettlementratedecreasedquickly.2.Hyperbolicmethodwasusedforoverloadmeasuredsettlementcurvefitting,whichverifiedeffectivestresscoefficientofpreloadingtreatmentmethod;hyperboliccur

6、vewasusedtopredictthefinalsettlementofsoftsoilfoundation,gettingabetterfittingeffect.3.Itcouldbeobtainedthroughanalysisthat,insoftsoilsubgradeengineering,subsidencecoefficientincreasedwithincreaseoffillingheight,densityandrate,decreasedwithdecreaseofthecrustlayerthicknessandthethickne

7、ssandstrengthofsoftsoil,anddecreasedwithchangeofthefoundationtype“simplepreloading→verticaldrainage→compositefoundation→compactionpile”.4.Combiningtheprojectpractice,thesedimentationcoefficientbysedimentationcoefficientformulacalculationwaslargerthanthesedimentationcoefficientbybackca

8、lcula